Plating selected areas of a metal web is effectively accomplished by compressing the metal web between resilient sealing masks with apertures in the mask designed to allow electrolyte to reach only the selected areas. Such apparatus is typified by U.S. Pat. No. 3,723,283 and especially sealing gasket 82 of FIG. 6 therein.
When precious metals are being plated, it is desirable to have very accurately located and sized apertures in these masks so that the apertures may be made smaller, plating less metal, while still retaining confidence that everything that needs to be plated, does indeed get plated. Prior art masks have thus been carefully hand assembled which is slow, tedious, expensive, and still not all that accurate. My invention overcomes these problems.